code: def _format_decision_tree(treedict):
      # type: (...) -> str
      if treedict.graphviz and _graphviz.is_supported():
          return _graphviz.dot2svg(treedict.graphviz)
      else:
          return tree2text(treedict)
  
imports: from __future__ import absolute_import
  from itertools import groupby
  from typing import List, Optional, Tuple
  import numpy
  from jinja2 import Environment, PackageLoader
  from eli5 import _graphviz
  from eli5.base import Explanation, TargetExplanation, FeatureWeights, FeatureWeight
  from eli5.utils import max_or_0
  from .utils import format_signed, format_value, format_weight, has_any_values_for_weights, replace_spaces, should_highlight_spaces
  from .None import fields
  from .features import FormattedFeatureName
  from .trees import tree2text
  from .text_helpers import prepare_weighted_spans, PreparedWeightedSpans
label_desc: Use image node_id 15 for calling a global function with example usage: _format_decision_tree(treedict) and returns: _graphviz, tree2text